'82 Crossfire with 700R4 tranny question

[nashville68bird]

I had my tranny shop pals rebuild the original tranny and have now put about 50 miles on her. For those of you that have this engine/tranny combo, you know that there is that ever-present "deadzone" when cruising roads at 40-50 MPH....the tranny slides in to fourth gear and the engine RPM drops to 1500 or so.....and now you are blogging down the road at what feels like too little RPM. I have a habit at that point of manually shifting down one notch and forcing her back in to third gear. I'd like to hear from you all if you feel doing this is detrimental to the powertrain, or if it is perfectly normal and safe to do so.

 

[KANE]

I have a 3.73 rear end and a crate motor now, but I remember the lugging at that speed and low RPM you are speaking of.

That dead spot is the result of the intersection of the RPM, speed, and torque curve.


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[nashville68bird]

Kane, do you think manually downshifting when in that situation would be detrimental to the transmission?

 

[stevolwevol]

You may get what you want if you adjust the transmission cable. When you pull it out, the higher RPM your tranny will shift. I have the cable all the way out on my 92 Camaro, but I still manually shift cause it upshifts too fast for me. It's not gonna hurt anything, and it's not really a problem as far as I'm concerned.

 

[nashville68bird]

You may get what you want if you adjust the transmission cable. When you pull it out, the higher RPM your tranny will shift. I have the cable all the way out on my 92 Camaro, but I still manually shift cause it upshifts too fast for me. It's not gonna hurt anything, and it's not really a problem as far as I'm concerned.

Thanks, Stevolwevol. I remember manually "shifting" the Powerglide auto tranny in my '68 Camaro for many years, and it took the beating and never failed me.

 

[stevolwevol]

Thanks, Stevolwevol. I remember manually "shifting" the Powerglide auto tranny in my '68 Camaro for many years, and it took the beating and never failed me.

Boy do I remember the powerglide! Anyway after answering your post, I forgot to mention that I manually shift almost every auto tranny on older Chevies. I usually never agree with the shift points, even with the TV cable adjusted properly, not to mention how boring it is just to put it in D. It is actually better for the clutches to shift firmly at a higher RPM, than a soft shift at lower revs.

 

[KANE]

I finally got my tranny back in. I have a 2k RPM stall converter in mine along with some changes to the governor springs.

FWIW... I am running the 82's OEM weights and then B&M blue and yellow springs.

I started out with a B&M purple and orange springs when I had the 2.87 rear end. When I put the 3.73 in it, I had step up to blue and green springs.

The new tranny seems a bit tighter which might explain why the need for a drop in springs again.




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[Lakeside49]

To answer your question directly, manually putting it into third gear at any point does no damage whatsoever. It simply puts the engine-trans back in a 1:1 ratio as is normal. GM engineering knew that people would do that, but they still got their CAFE improvement credit that they badly needed that year.
I installed a HyperTech chip in the ECM that significantly improved the points where it locks up in overdrive which was too soon at any given time. I would never go back to the stock chip


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[82ColEd]

To answer your question directly, manually putting it into third gear at any point does no damage whatsoever. It simply puts the engine-trans back in a 1:1 ratio as is normal. GM engineering knew that people would do that, but they still got their CAFE improvement credit that they badly needed that year.
I installed a HyperTech chip in the ECM that significantly improved the points where it locks up in overdrive which was too soon at any given time. I would never go back to the stock chip


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Mine is bone stock, but yes. If it ticks me off, i put her into 3rd. Mostly though i do that when it's not behaving as it should as my Mechanic adjusted the tranny cable to shift, so currently no need for the kick down out of Overdrive to 3rd as it shifts back down by itself. But, yes, no harm is to be expected.. Then again, they ARE 35.. :L


Stefan

 

[KANE]

Before I added the bigger can and changed the power and, the factory shift points were just fine and I drove it around in third until I was habitually over 45 or 50 miles an hour.

Even now on a 3.73, I still find that I use drive a lot more than overdrive.

The most important thing to do is to make sure the TV cable is set right. You cannot use the TV cable to set the WOT shift points – you can only use it to adjust when they occur and how it feels.